The Resilience Deformation Rules Test Research of the Soft Soil in the Unloading Condition

2011 ◽  
Vol 243-249 ◽  
pp. 2560-2564
Author(s):  
Bin Tang ◽  
Ren Wang ◽  
Jun Lei
Keyword(s):  
Laboratory Test ◽  
Void Ratio ◽  
Triaxial Compression ◽  
Soft Soil

The resilience deformation rules laboratory test research of the soft soil in the Wuhan region in the unloading condition is done through modified triaxial compression apparatus .And the result shows:(1)the critical unloading ratios of the soft soil in Wuhan region is 0.28 and 0.91.No matter the unloading amount is, no resilience deformation is produced when the unloading ratio is smaller than 0.28 or larger than 0.91,and the resilience deformation is produced when the unloading ration is between 0.28 and 0.91.(2)The void ratio is related to the initial preloading ,the bigger the preloading, the smaller the void ratio, and the bigger the increasing of the void ratio after unloading; the smaller the initial preloading ,the bigger the void ratio, and the smaller the increasing of the void ratio after unloading.(3)The peak resilience rate is linear to the initial preloading.

scholarly journals Experimental Study on Improvement of Marine Soft Soil with Alkali Residue

2018 ◽  
Vol 53 ◽  
pp. 04021
Author(s):  
SHAO Yong ◽  
LIU Xiao-li ◽  
ZHU Jin-jun
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Void Ratio ◽  
Soft Soil ◽  
Compressive Modulus ◽  
Engineering Properties ◽  
Test Results ◽  
Use Of Resources ◽  
One Year

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.

Consolidation Properties of Ho Chi Minh City Soil, Vietnam

2020 ◽  
Vol 54 (1A) ◽  
pp. 1-10
Author(s):  
Vo Nhat Luan
Keyword(s):  
Void Ratio ◽  
Soft Soil ◽  
Liquid Limit ◽  
Ho Chi Minh City ◽  
Compression Index ◽  
Underground Structures ◽  
Compression Pressure ◽  
Coefficient Of Consolidation ◽  
Two Samples ◽  
Index Changes

This paper presents the experimental results of consolidation properties of soft soil in Ho Chi Minh City of Vietnam. Forty-two samples were collected from different locations and were determined in the laboratory by Oedometer test. The results showed that the coefficient of consolidation of soft soil varies from 0.052.10-3 to 3.3.10-3cm2/s, otherwise the compression index changes from 0.156 to 1.703, soil is in a normally consolidated or over the consolidated state. These properties also change differently with depth. It also indicated that the compressive index of soft soil has a fine linear relationship with the liquid limit، water content, and void ratio. The coefficient of consolidation of soft soil decreases with the increase of compression pressure. These parameters are basic for calculating the settlement of underground structures in Ho Chi Minh City.

SOFT SOIL IMPROVEMENT USING CHEMICAL-RUBBER CHIPS MIXTURE

2015 ◽  
Vol 76 (2) ◽  
Author(s):  
Aminaton Marto ◽  
Norazirah Aziz ◽  
Mohammed Ridzuan Jahidin ◽  
Nor Zurairahetty Mohd Yunus ◽  
Fauziah Kasim ◽  
...  
Keyword(s):  
Void Ratio ◽  
Soft Soil ◽  
Soil Improvement ◽  
Soil Test ◽  
Unconfined Compression ◽  
Marine Clay ◽  
Untreated Sample ◽  
Unconfined Compression Test ◽  
Soft Soils ◽  
Clay Particles

Soft soils are widely found in many areas around the world as well as in Malaysia. Marine clay is one of the problematic soft soils. The marine clay should be pretreated before the construction to enhance the usability and serviceability of highway constructed on this type of soil. This paper presents the research results on the usability of chemical (SH-85)-rubber chips mixtures as the stabilizing agent in improving the characteristics of marine clay from two engineering perspectives; the strength and the compressibility. Three types of laboratory tests were conducted; index soil test, unconfined compression test and oedometer test. The results show that the treated samples had higher unconfined compressive strength compared to untreated sample. The strength of marine clay increased when the amount of the SH-85 increased.  The void ratio reduced in value when the chemical-rubber chips mixture was added to the marine clay. It is due to the chemical that acts as a binder that interlocks the rubber chips and the marine clay particles, reducing the compressibility. It has been concluded that the mixture of chemical-rubber chips with 8 % SH-85 plus 1 % of rubber chips is more effectively improved the characteristics of marine clay.  

Mode of shear effects on yield and liquefied strength ratios

2008 ◽  
Vol 45 (4) ◽  
pp. 574-587 ◽  
Author(s):  
Scott M. Olson ◽  
Benjamin B. Mattson
Keyword(s):  
Simple Shear ◽  
Void Ratio ◽  
Triaxial Compression ◽  
State Parameter ◽  
Sloping Ground ◽  
Direct Simple Shear ◽  
Flow Failure ◽  
Triaxial Extension Test ◽  
Triaxial Extension ◽  
Rotational Shear

A database of 386 laboratory triaxial compression, direct simple shear, rotational shear, and triaxial extension test results was collected to examine yield and liquefied strength ratio concepts used in liquefaction analysis of sloping ground. These data envelope the yield and liquefied strength ratios obtained from back-analyses of liquefaction flow failure case histories. Generally, triaxial compression exhibits the highest yield and liquefied strength ratios, triaxial extension yields the lowest ratios, and direct simple shear – rotational shear shows intermediate responses. However, mode of shear appears to have a considerably smaller effect on laboratory-measured liquefied strength ratios for specimens with a positive state parameter (i.e., difference in consolidation void ratio and steady state void ratio at the same effective stress).

Experimental Study on Shear Strength Considering Initial Void Ratio and Plasticity Index

2013 ◽  
Vol 405-408 ◽  
pp. 63-67
Author(s):  
Xing Chen Wang ◽  
Ri Qing Xu ◽  
Jian Feng Zhu
Keyword(s):  
Shear Strength ◽  
Void Ratio ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Deviatoric Stress ◽  
Plasticity Index ◽  
Test Results ◽  
Compression Tests ◽  
Functional Relationships ◽  
Initial Void Ratio

A series of drained triaxial compression tests under different conditions were performed to quantitatively study the influence of the initial void ratio and plasticity index on the shear strength of remolded saturated clays. The test results show that both the peak stress friction angle and peak deviatoric stress decrease with increasing initial void ratio and plasticity index of the soil under the same confining pressure; whereas, they increase with increasing confining pressure of the soil under the same initial void ratio and plasticity index. A new synthesized physical parameter λ, which simultaneously represent both the type and the condition of remolded saturated clays, is defined based on the test results in this work. The functional relationships among the parameters φd and peak deviatoric stress in Mohr-Coulomb equation and the parameter λ are established to develop a modified Mohr-Coulomb equation by considering physical properties of soil. In this equation, only two input parameters, i.e., λ and the confine pressure, are needed to predict the shear strength of the soil. In order to check the accuracy of the proposed equation, laboratory tests were conducted to evaluate against the predicted results. The results show that the peak shear strength of remolded saturated clays can be well described by the proposed equation. Key words: shear strength; Mohr-Coulomb equation; remolded saturated clays; initial void ratio; plasticity index.

scholarly journals Geotechnical Properties of Soft Marine Soil at Chan May Port, Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Nu NGUYEN ◽  
Thanh Duong NGUYEN ◽  
Truong Son BUI
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Void Ratio ◽  
Soft Soil ◽  
Field Investigation ◽  
Liquid Limit ◽  
Geotechnical Properties ◽  
Unit Weight ◽  
Dry Unit Weight ◽  
Marine Soil

Soft marine soil deposit is distributed under the sea with many special properties. This type ofsoil is rarely researched in Vietnam because of the difficult geotechnical investigation under the sea level.In this paper, the experimental laboratories were performed to investigate the geotechnical properties ofsoft marine soil at Chan May port, Vietnam. The field investigation results indicate that the thickness ofsoft soil varies from a few meters to more than ten meters. Soft soil has a high value of water content,void ratio, and compressibility and a low value of shear strength. The compression index has a goodrelationship with water content, liquid limit, and dry unit weight. The unit weight, shear strength, and preconsolidationpressure increase with the increase of depth. These results show that the soil in the studyarea is unfavorable for construction activities.

Estimating the undrained strength of sand: a theoretical framework

1995 ◽  
Vol 32 (5) ◽  
pp. 859-870 ◽  
Author(s):  
Catherine E. Fear ◽  
Peter K. Robertson
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Void Ratio ◽  
Triaxial Compression ◽  
State Parameter ◽  
In Situ Tests ◽  
Initial State ◽  
Undrained Strength

A framework for estimating the ultimate undrained steady state shear strength of sand (Su) from in situ tests, which combines the theory of critical state soil mechanics with shear wave velocity measurements, is presented. For a particular direction of undrained loading, samples of a given sand at a constant void ratio will reach the same Su, despite the magnitude of the initial effective confining stresses. Unique Su/p′ or [Formula: see text] ratios for a given direction of loading exist for a particular sand only if state parameter is constant throughout the deposit. Normalized shear wave velocity, Vs1, can be correlated with void ratio and is therefore used to estimate Su for a given initial state and direction of loading. Strengths in triaxial compression are examined in this paper; however, the same framework can be used to estimate strengths under other directions of loading. The Su–Vs1 relationship is shown to be relatively sensitive and should be used more as a screening tool rather than an accurate means of predicting Su. Vs1 is converted to equivalent values of SPT (N1)60 and CPT qc1, and the results are compared with the current methods of estimating Su. Key words : in situ testing, liquefaction, sand, undrained strength.

Influence of silt size and content on liquefaction behavior of sands

2011 ◽  
Vol 48 (6) ◽  
pp. 931-942 ◽  
Author(s):  
Mehmet Murat Monkul ◽  
Jerry A. Yamamuro
Keyword(s):  
Void Ratio ◽  
Triaxial Compression ◽  
Relative Size ◽  
Silty Sand ◽  
Engineering Practice ◽  
Compression Tests ◽  
Confining Stress ◽  
Liquefaction Potential ◽  
Fines Content ◽  
Triaxial Compression Tests

This study investigates the fines content influence on liquefaction potential of a single base sand mixed with three different essentially nonplastic silts through strain-controlled monotonic undrained triaxial compression tests. Confining stress (30 kPa) and deposition method (dry funnel deposition) were kept the same, while fines content was varied, to solely focus on how different silts and their contents influence the undrained response of the sand under comparable conditions. It was found that if the mean grain diameter ratio (D50-sand/d50-silt) of the sand grains to silt grains is sufficiently small, the liquefaction potential of the sand increases steadily with increasing fines content for the studied range (0%–20%). As D50-sand/d50-silt increases, the liquefaction potential of the silty sand might actually be less than the liquefaction potential of the clean sand. Test results also revealed that commonly used comparison bases (i.e., void ratio, intergranular void ratio, relative density) are not sufficient for assessing the influence of fines on liquefaction potential of silty sands. Finally, relative size of the silt grains should also be considered in geotechnical engineering practice in addition to content and plasticity of fines to characterize the influence of silt on liquefaction potential of sands.

Specimen nonuniformities in water-pluviated and moist-tamped sands under undrained triaxial compression and extension

2008 ◽  
Vol 45 (7) ◽  
pp. 939-956 ◽  
Author(s):  
P. R. Thomson ◽  
R. C.K. Wong
Keyword(s):  
Computed Tomography ◽  
Axial Load ◽  
Void Ratio ◽  
Triaxial Compression ◽  
Stress Path ◽  
Saturated Sand ◽  
Ratio Distribution ◽  
X Ray ◽  
X Ray Computed ◽  
Insight Into

X-ray computed tomography (CT) methods and specialized triaxial equipment were developed to quantify void ratio distribution within saturated sand specimens reconstituted by water pluviation and moist tamping methods during undrained triaxial compression and extension. The CT measurements were obtained at several points along the stress path of each specimen without significant removal of axial load. It was observed that two reconstitution methods yielded very different void ratio distributions within specimens. Significant void ratio redistribution occurred within each specimen during the undrained shearing tests. The influences of void ratio redistribution on globally observed specimen responses are discussed. The findings of this research investigation provide unique insight into fundamental aspects of saturated sand behaviour during undrained triaxial shearing.

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